By Tanner Stransky
Updated September 18, 2009 at 09:56 AM EDT

Sideways star Paul Giamatti has signed up to play the tyrant King John in Ironclad, a medieval action drama that being shooting in Wales next month, according to Variety. He’ll star alongside Rome and The Philanthropist star James Purefoy. The drama centers around a familiar-sounding tale that finds the Knights Templar (Purefoy) and his seven cohorts defending Rochester Castle against King John in 13th century England.